Back to 2014-2018 Mazda Mazda3

2014-2018 MAZDA MAZDA3

2.5L I4FWDAUTOMATICgas
20 active safety recalls on this vehicle — view recalls
Repairs0Labor479Torque4866Fluid6DTC917Battery0Maintenance0Recalls20
P0038low severityPowertrain

HO2S Heater Control Circuit High Bank 1 Sensor 2

on 2014-2018 Mazda Mazda3 2.5L I4 · FWD

What this code means

The voltage in the Bank 1 Sensor 2 O2 heater circuit is higher than expected.

Symptoms

  • Check Engine Light
  • Possible overheating

Common causes

  • Short to power
  • Faulty sensor
  • Relay issue

Diagnostic steps

  1. Test heater voltage
  2. Check for shorts to power
  3. Test resistance

Repair notes

Repair short or replace sensor.

Other Powertrain codes on this vehicle

Building an app?
Free API access to all this data — 50 requests/day, no card required.
Get an API key →
Run a shop?
Manage repairs, estimates, and customers with ShopBase — $249/mo, all features included.
Try ShopBase →